The gravitational force between two objects is 45,000 N. What will be the gravitational force between the two objects if the distance between the objects is reduced by one-half?

180000 N

Explanation:

According to Newton's law of gravitation

F= G m1 m2 / r^2

This expression shows that if distance is reduced to half the gravitational force will increase 4 times.

two charges are fixed in place on the x-axis as shown. the charge at x = 0 is negative and has magnitude q = 2 μcoulombs (1 μcoulomb = 10-6 coulombs). the charge at x = d, (d = +12 cm), is positive and has magnitude q = 4 μcoulombs. find a point x = xo along the x-axis at which the electric field is zero.

when a device is used in a circuit in which the voltage is 81 v, the current flowing through the device is 3 a. what is the resistance of the device?

a. 27 ω

b. 40.5 a

c. 243 ω

d. 243 a

the correct answer is a. 27